Orchid Extinction Over the Last 150 Years in the Czech Republic
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diversity Article Orchid Extinction over the Last 150 Years in the Czech Republic Zuzana Štípková 1,2,* and Pavel Kindlmann 1,2 1 Global Change Research Institute, Academy of Sciences of the Czech Republic, Bˇelidla986/4a, 60300 Brno, Czech Republic; [email protected] 2 Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, 12801 Prague, Czech Republic * Correspondence: [email protected]; Tel.: +420-7367-31008 Abstract: Understanding temporal changes in the distribution and abundance of various species is one of the key goals of conservation biology. During recent decades, the abundance and distribution of many species of plants and animals have declined dramatically, mainly because of habitat loss and fragmentation. The purpose of this study is to analyze the rate of extinction of orchids at various sites in different 20-year time intervals over the last 150 years, determined according to changes in society. Using the dataset of the orchid records of the Nature Conservation Agency of the Czech Republic, we determined the disappearance rate of orchids from sites using a grid of 1 × 1 km. We found that the vast majority of orchids disappeared from many of their historical localities in all time intervals analyzed. The number of sites suitable for Czech orchids declined by 8–92%, depending on the species. The most threatened orchid species in the Czech Republic are Spiranthes spiralis, Anacamptis palustris, Epipogium aphyllum and Goodyera repens. This all seems to be closely related with changes in agricultural practices in the open as well as in forest habitats. Preserving suitable orchid habitats seems to be the key for keeping Czech orchid flora alive. Keywords: conservation; number of sites; critically endangered orchids; threatened Citation: Štípková, Z.; Kindlmann, P. Orchid Extinction over the Last 150 Years in the Czech Republic. Diversity 2021, 13, 78. https://doi.org/ 10.3390/d13020078 1. Introduction One of the most important issues of modern conservation biology is to understand Academic Editors: Mark Brundrett temporal changes in the distribution and abundance of various species [1]. During recent and Mario A. Pagnotta decades, the human impact on natural resources and habitats has caused a dramatically large extinction rate and a decline in the number of sites suitable for many plants and Received: 15 January 2021 animals [2–7], with habitat loss and fragmentation being the most important factors [2,3]. Accepted: 9 February 2021 Mankind has had a very marked effect on Europe, especially its rapid industrial devel- Published: 13 February 2021 opment in recent centuries, which has resulted in a highly fragmented and degraded landscape [8]. The current land cover in Europe is mainly a result of farming and demo- Publisher’s Note: MDPI stays neutral graphic trends over recent decades [9]. In general, urbanization, changes in land use and with regard to jurisdictional claims in the intensification of agriculture are the most important factors that have resulted in habitat published maps and institutional affil- destruction in many parts of Europe [5,6,10–12]. iations. In the past, there were important changes in the use of land in the Czech Republic (Czechoslovakia, until the splitting of the country in 1993), which differed from those that occurred in Western Europe because of the differences in the political regimes in Central and Western Europe [13,14]. Before 1948, fields and meadows were traditionally managed [15], Copyright: © 2021 by the authors. which involved mowing and grazing, low intensity agriculture of small fields and low Licensee MDPI, Basel, Switzerland. application of fertilizers [14]. After 1948, small fields were combined into huge fields [16] This article is an open access article and subsidies for fertilizers were provided, which resulted in the amount of chemicals distributed under the terms and in the soil increasing rapidly [14]. After the change of regime in 1989, the subsidies for conditions of the Creative Commons fertilizers stopped, which resulted in a great decline in the use of fertilizers [17]. Attribution (CC BY) license (https:// In this study, we concentrate on orchids, because orchids are considered to be one of the creativecommons.org/licenses/by/ most threatened groups of species worldwide [18–20]. With approximately 28,500 species [21], 4.0/). Diversity 2021, 13, 78. https://doi.org/10.3390/d13020078 https://www.mdpi.com/journal/diversity Diversity 2021, 13, 78 2 of 15 Orchidaceae is one of the most diverse and widespread families of flowering plant [18]. Unfortunately, most species of orchids are threatened in the wild [22] and are disappearing from their natural habitats worldwide [7,22–24]. In Europe, the main reasons for this dra- matic decline are habitat loss, eutrophication and fragmentation [12,23,25–28]. Their typical low pollination success and low levels of fruit set, as well as environmental heterogeneity, are also linked to their rarity [29–31]. Because of the activities of professionals and amateurs, orchids are well recorded and studied in many countries in Europe [32]. The availability of detailed records collected over long periods of time provides opportunities for comparative analyses of the declines of a species over time [23]. Identification of environmental factors and species traits that are correlated with the decline in the orchid’s distribution could result in improvements in the management of valuable habitats [23]. However, despite the increasing number of studies dealing with orchid distribution in different parts of the world e.g., [33–38], there is scarce information available on orchid conservation and the drivers of their extinction [31,39]. An important category of orchids that requires special conservation measures is those orchids classified in the most threatened category according either to the IUCN guidelines or other national classifications e.g., [8,40,41]. These lists of species provide essential information on trends in the loss of biodiversity [42–44]. Red List assessments often differ among countries [45] and are therefore more appropriate for local conditions than IUCN Red List categories and criteria [46], which were built to be as general as possible. However, some general patterns at the landscape level might be found using national Red List data [43,47]. Therefore, we use the latest Czech Red List [48] here. The aim of this study was to analyze the trends in the changes in the number of sites of rare species of orchids (those classified as “critically endangered” and “extinct” based on the national Red Lists) [40,41,48]. We attempted to put the available data into context with shifts in agricultural practices. We asked the following questions: From what percentage of historically known sites did orchids disappear over the time period covered by our database (about 150 years)? Is there any difference in the number of sites from which orchids disappeared before, during and after the communist period in the Czech Republic? Which species of orchids in the Czech Republic are most in danger of becoming extinct, based on the percentage of historical sites still occupied? 2. Materials and Methods 2.1. Study Site The Czech Republic is in central Europe and its flora is very well studied. Its average altitude is 450 m above sea level, a calculation based on the 30-sec altitude layer [49] and performed in ArcMap 10.1 [50]. The country is covered mainly by highlands of moderate altitude, whereas higher mountains occur at the borders with other countries (mainly in the north and south). The climate of the Czech Republic is typically temperate, with cold, cloudy winters and hot summers. However, there are some regional and local differences due to the relief that forms the complex topography in this area [51]. Because the Czech Republic is a relatively small country in terms of latitude range, temperature and precipitation are mostly affected by local heterogeneity and altitude [52]. 2.2. The Database The dataset of orchid records we used is based on that of the Nature Conservation Agency of the Czech Republic, which is not freely accessible. The records cover a period of about 150 years and include all known literature and reports from people on the records of orchids, the identities of which are subsequently checked by specialists. The database includes more than 115,000 individual records. Each site is characterized by its GPS coordinates. Because of the high number of records and the extremely long timespan covered, the cross-checking procedure for dupli- cate records was not consistently conducted, especially in the older data. This means that Diversity 2021, 13, 78 3 of 15 in many cases, the same site may be called different names and the GPS coordinates may differ for the same sites in different records in the database. We resolved this problem by using ArcMap 10.1 [50] to create a grid of 1 × 1 km squares. For each square, we then considered any recording with its GPS coordinates falling within this square as the same site. This is reasonable, as typical orchid sites cover several thousand square meters, and small adjacent sites are likely to be sub-sites of a larger site, or, in other words, an orchid meta-population. For each of the sites (squares in our grid where an orchid population was recorded), we determined the latest year when orchids were still present at the site. If the year was 1990 or later, the site was considered still occupied (except in the case of two species mentioned in Section 3.1, which are commonly considered extinct in the Czech Republic, despite being found during 1990–2020). If the last record of an extant population at a site was prior to 1990, this date was considered to be the date of extinction of the orchid population at this site. It is unlikely that this resulted in a bias in our calculations.